THE HIGHER OEGANISMS 155 



has its beginning in some external impression. Those 

 who doubt this may amuse themselves by endeavoring 

 to create something in thought. 



It is not the purpose of this writing to indulge in the 

 deeper problems of psychology or to enter the domain of 

 metaphysics. Consciousness, the highest of the nervous 

 phenomena remains unexplained. As, however, con- 

 sciousness implies the possession of those special senses 

 by which knowledge of the external world can be at- 

 tained, and is discovered only after a certain intellectual 

 development has been reached; as it is apparently ab- 

 sent in idiots and may be lost in disease, injury, or anaes- 

 thesia, there can be no doubt but that it is a function 

 centred in the nervous system, and that it depends upon 

 the complexity of that system and the correlation of its 

 cell impressions or memories. 



But the higher animals not only live in adjustment 

 to the external world; they have internal organs whose 

 functions are indispensable, and upon whose coordi- 

 nated activities the life of the whole body depends. For 

 these there must be governing mechanisms, and chief 

 among them we again find the nervous system. Here, 

 however, automaticity of operation and properly cor- 

 related action are the chief requirements. These func- 

 tions progress without intellection. The nervous ar- 

 rangements by which this work is done, therefore, forms 

 an almost independent system, the sympathetic system, by 

 which the organs are automatically innervated. Thus, 

 the heart beats continually automatically by virtue 

 of its inherent ganglia, though it communicates with 

 the central nervous system through the vagus nerves 

 and is impressed by general psychic conditions. It is 

 difficult to trace the inception of this part of the nervous 

 system, as automatic action, such as it supplies to the 

 organs of the higher animals, is one of the first functions 

 to make its appearance in the lower forms of life. No 

 separation of the two branches of the nervous system 

 into sensory-motor and sympathetic systems can be 



